/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2011-2018 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "vtkPVFoam.H"
#include "vtkPVFoamReader.h"

// OpenFOAM includes
#include "fvMesh.H"
#include "Time.H"
#include "patchZones.H"
#include "collatedFileOperation.H"
#include "etcFiles.H"

// VTK includes
#include "vtkDataArraySelection.h"
#include "vtkMultiBlockDataSet.h"
#include "vtkRenderer.h"
#include "vtkTextActor.h"
#include "vtkTextProperty.h"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
    defineTypeNameAndDebug(vtkPVFoam, 0);
}


// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //

#include "vtkPVFoamAddToSelection.H"
#include "vtkPVFoamUpdateInfoFields.H"

void Foam::vtkPVFoam::resetCounters()
{
    // Reset array range information (ids and sizes)
    arrayRangeVolume_.reset();
    arrayRangePatches_.reset();
    arrayRangeLagrangian_.reset();
    arrayRangeCellZones_.reset();
    arrayRangeFaceZones_.reset();
    arrayRangePointZones_.reset();
    arrayRangeCellSets_.reset();
    arrayRangeFaceSets_.reset();
    arrayRangePointSets_.reset();
}


void Foam::vtkPVFoam::reduceMemory()
{
    forAll(regionPolyDecomp_, i)
    {
        regionPolyDecomp_[i].clear();
    }

    forAll(zonePolyDecomp_, i)
    {
        zonePolyDecomp_[i].clear();
    }

    forAll(csetPolyDecomp_, i)
    {
        csetPolyDecomp_[i].clear();
    }

    if (!reader_->GetCacheMesh())
    {
        delete meshPtr_;
        meshPtr_ = nullptr;
    }
}


int Foam::vtkPVFoam::setTime(int nRequest, const double requestTimes[])
{
    Time& runTime = dbPtr_();

    // Get times list. Flush first to force refresh.
    fileHandler().flush();
    instantList Times = runTime.times();

    int nearestIndex = timeIndex_;
    for (int requestI = 0; requestI < nRequest; ++requestI)
    {
        int index = Time::findClosestTimeIndex(Times, requestTimes[requestI]);
        if (index >= 0 && index != timeIndex_)
        {
            nearestIndex = index;
            break;
        }
    }

    if (nearestIndex < 0)
    {
        nearestIndex = 0;
    }

    if (debug)
    {
        Info<< "<beg> Foam::vtkPVFoam::setTime(";
        for (int requestI = 0; requestI < nRequest; ++requestI)
        {
            if (requestI)
            {
                Info<< ", ";
            }

            Info<< requestTimes[requestI];
        }
        Info<< ") - previousIndex = " << timeIndex_
            << ", nearestIndex = " << nearestIndex << endl;
    }


    // see what has changed
    if (timeIndex_ != nearestIndex)
    {
        timeIndex_ = nearestIndex;
        runTime.setTime(Times[nearestIndex], nearestIndex);

        // the fields change each time
        fieldsChanged_ = true;

        if (meshPtr_)
        {
            if (meshPtr_->readUpdate() != polyMesh::UNCHANGED)
            {
                meshChanged_ = true;
            }
        }
        else
        {
            meshChanged_ = true;
        }
    }

    if (debug)
    {
        Info<< "<end> Foam::vtkPVFoam::setTime() - selectedTime="
            << Times[nearestIndex].name() << " index=" << timeIndex_
            << "/" << Times.size()
            << " meshChanged=" << Switch(meshChanged_)
            << " fieldsChanged=" << Switch(fieldsChanged_) << endl;
    }

    return nearestIndex;
}


void Foam::vtkPVFoam::updateMeshPartsStatus()
{
    if (debug)
    {
        Info<< "<beg> Foam::vtkPVFoam::updateMeshPartsStatus" << endl;
    }

    vtkDataArraySelection* selection = reader_->GetPartSelection();
    label nElem = selection->GetNumberOfArrays();

    if (partStatus_.size() != nElem)
    {
        partStatus_.setSize(nElem);
        partStatus_ = false;
        meshChanged_ = true;
    }

    // this needs fixing if we wish to re-use the datasets
    partDataset_.setSize(nElem);
    partDataset_ = -1;

    // Read the selected mesh parts (zones, patches ...) and add to list
    forAll(partStatus_, partId)
    {
        const int setting = selection->GetArraySetting(partId);

        if (partStatus_[partId] != setting)
        {
            partStatus_[partId] = setting;
            meshChanged_ = true;
        }

        if (debug)
        {
            Info<< "  part[" << partId << "] = "
                << partStatus_[partId]
                << " : " << selection->GetArrayName(partId) << endl;
        }
    }
    if (debug)
    {
        Info<< "<end> Foam::vtkPVFoam::updateMeshPartsStatus" << endl;
    }
}


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

Foam::vtkPVFoam::vtkPVFoam
(
    const char* const vtkFileName,
    vtkPVFoamReader* reader
)
:
    reader_(reader),
    dbPtr_(nullptr),
    meshPtr_(nullptr),
    meshRegion_(polyMesh::defaultRegion),
    meshDir_(polyMesh::meshSubDir),
    timeIndex_(-1),
    meshChanged_(true),
    fieldsChanged_(true),
    arrayRangeVolume_("unzoned"),
    arrayRangePatches_("patches"),
    arrayRangeLagrangian_("lagrangian"),
    arrayRangeCellZones_("cellZone"),
    arrayRangeFaceZones_("faceZone"),
    arrayRangePointZones_("pointZone"),
    arrayRangeCellSets_("cellSet"),
    arrayRangeFaceSets_("faceSet"),
    arrayRangePointSets_("pointSet")
{
    if (debug)
    {
        Info<< "Foam::vtkPVFoam::vtkPVFoam - " << vtkFileName << endl;
        printMemory();
    }

    fileName FileName(vtkFileName);

    // avoid argList and get rootPath/caseName directly from the file
    fileName fullCasePath(FileName.path());

    if (!isDir(fullCasePath))
    {
        return;
    }
    if (fullCasePath == ".")
    {
        fullCasePath = cwd();
    }


    if (fullCasePath.name().find("processors", 0) == 0)
    {
        // FileName e.g. "cavity/processors256/processor1.OpenFOAM
        // Remove the processors section so it goes into processorDDD
        // checking below.
        fullCasePath = fullCasePath.path()/fileName(FileName.name()).lessExt();
    }


    if (fullCasePath.name().find("processor", 0) == 0)
    {
        // Give filehandler opportunity to analyse number of processors
        (void)fileHandler().filePath(fullCasePath);

        const fileName globalCase = fullCasePath.path();

        setEnv("FOAM_CASE", globalCase, true);
        setEnv("FOAM_CASENAME", globalCase.name(), true);
    }
    else
    {
        setEnv("FOAM_CASE", fullCasePath, true);
        setEnv("FOAM_CASENAME", fullCasePath.name(), true);
    }

    // look for 'case{region}.OpenFOAM'
    // could be stringent and insist the prefix match the directory name...
    // Note: cannot use fileName::name() due to the embedded '{}'
    string caseName(FileName.lessExt());
    string::size_type beg = caseName.find_last_of("/{");
    string::size_type end = caseName.find('}', beg);

    if
    (
        beg != string::npos && caseName[beg] == '{'
     && end != string::npos && end == caseName.size()-1
    )
    {
        meshRegion_ = caseName.substr(beg+1, end-beg-1);

        // some safety
        if (meshRegion_.empty())
        {
            meshRegion_ = polyMesh::defaultRegion;
        }

        if (meshRegion_ != polyMesh::defaultRegion)
        {
            meshDir_ = meshRegion_/polyMesh::meshSubDir;
        }
    }

    if (debug)
    {
        Info<< "fullCasePath=" << fullCasePath << nl
            << "FOAM_CASE=" << getEnv("FOAM_CASE") << nl
            << "FOAM_CASENAME=" << getEnv("FOAM_CASENAME") << nl
            << "region=" << meshRegion_ << endl;
    }

    // Pre-load any libraries
    dlLibraryTable dlTable;

    string libsString(getEnv("FOAM_LIBS"));
    if (!libsString.empty())
    {
        IStringStream is(libsString);
        fileNameList libNames(is);
        forAll(libNames, i)
        {
            dlTable.open(libNames[i]);
        }
    }

    // Create time object
    dbPtr_.reset
    (
        new Time
        (
            Time::controlDictName,
            fileName(fullCasePath.path()),
            fileName(fullCasePath.name())
        )
    );

    dbPtr_().functionObjects().off();

    fileNameList configDictFiles = findEtcFiles("paraFoam", false);
    forAllReverse(configDictFiles, cdfi)
    {
        configDict_.merge(dictionary(IFstream(configDictFiles[cdfi])()));
    }

    updateInfo();
}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::vtkPVFoam::~vtkPVFoam()
{
    if (debug)
    {
        Info<< "<end> Foam::vtkPVFoam::~vtkPVFoam" << endl;
    }

    delete meshPtr_;
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void Foam::vtkPVFoam::updateInfo()
{
    if (debug)
    {
        Info<< "<beg> Foam::vtkPVFoam::updateInfo"
            << " [meshPtr=" << (meshPtr_ ? "set" : "nullptr") << "] timeIndex="
            << timeIndex_ << endl;
    }

    resetCounters();

    vtkDataArraySelection* partSelection = reader_->GetPartSelection();

    // there are two ways to ensure we have the correct list of parts:
    // 1. remove everything and then set particular entries 'on'
    // 2. build a 'char **' list and call SetArraysWithDefault()
    //
    // Nr. 2 has the potential advantage of not touching the modification
    // time of the vtkDataArraySelection, but the qt/paraview proxy
    // layer doesn't care about that anyhow.

    // enable 'internalMesh' on the first call
    // or preserve the enabled selections
    stringList enabledEntries;
    bool first = !partSelection->GetNumberOfArrays() && !meshPtr_;
    if (first)
    {
        enabledEntries.setSize(1);
        enabledEntries[0] = "internalMesh";
    }
    else
    {
        enabledEntries = getSelectedArrayEntries(partSelection);
    }

    // Clear current mesh parts list
    partSelection->RemoveAllArrays();

    // Update mesh parts list - add Lagrangian at the bottom
    updateInfoInternalMesh(partSelection);
    updateInfoPatches(partSelection, enabledEntries, first);
    updateInfoSets(partSelection);
    updateInfoZones(partSelection);
    updateInfoLagrangian(partSelection);

    // restore the enabled selections
    setSelectedArrayEntries(partSelection, enabledEntries);

    if (meshChanged_)
    {
        fieldsChanged_ = true;
    }

    // Update volume, point and lagrangian fields
    updateInfoFields<fvPatchField, volMesh>
    (
        reader_->GetVolFieldSelection()
    );
    updateInfoFields<pointPatchField, pointMesh>
    (
        reader_->GetPointFieldSelection()
    );
    updateInfoLagrangianFields();

    if (debug)
    {
        // just for debug info
        getSelectedArrayEntries(partSelection);
        Info<< "<end> Foam::vtkPVFoam::updateInfo" << endl;
    }

}


void Foam::vtkPVFoam::updateFoamMesh()
{
    if (debug)
    {
        Info<< "<beg> Foam::vtkPVFoam::updateFoamMesh" << endl;
        printMemory();
    }

    if (!reader_->GetCacheMesh())
    {
        delete meshPtr_;
        meshPtr_ = nullptr;
    }

    // Check to see if the OpenFOAM mesh has been created
    if (!meshPtr_)
    {
        if (debug)
        {
            Info<< "Creating OpenFOAM mesh for region " << meshRegion_
                << " at time=" << dbPtr_().timeName()
                << endl;

        }

        meshPtr_ = new fvMesh
        (
            IOobject
            (
                meshRegion_,
                dbPtr_().timeName(),
                dbPtr_(),
                IOobject::MUST_READ
            )
        );

        meshChanged_ = true;
    }
    else
    {
        if (debug)
        {
            Info<< "Using existing OpenFOAM mesh" << endl;
        }
    }

    if (debug)
    {
        Info<< "<end> Foam::vtkPVFoam::updateFoamMesh" << endl;
        printMemory();
    }
}


void Foam::vtkPVFoam::Update
(
    vtkMultiBlockDataSet* output,
    vtkMultiBlockDataSet* lagrangianOutput
)
{
    if (debug)
    {
        cout<< "<beg> Foam::vtkPVFoam::Update - output with "
            << output->GetNumberOfBlocks() << " and "
            << lagrangianOutput->GetNumberOfBlocks() << " blocks\n";
        output->Print(cout);
        lagrangianOutput->Print(cout);
        printMemory();
    }
    reader_->UpdateProgress(0.1);

    // Set up mesh parts selection(s)
    updateMeshPartsStatus();

    reader_->UpdateProgress(0.15);

    // Update the OpenFOAM mesh
    updateFoamMesh();
    reader_->UpdateProgress(0.4);

    // Convert meshes - start port0 at block=0
    int blockNo = 0;

    convertMeshVolume(output, blockNo);
    convertMeshPatches(output, blockNo);
    reader_->UpdateProgress(0.6);

    if (reader_->GetIncludeZones())
    {
        convertMeshCellZones(output, blockNo);
        convertMeshFaceZones(output, blockNo);
        convertMeshPointZones(output, blockNo);
        reader_->UpdateProgress(0.65);
    }

    if (reader_->GetIncludeSets())
    {
        convertMeshCellSets(output, blockNo);
        convertMeshFaceSets(output, blockNo);
        convertMeshPointSets(output, blockNo);
        reader_->UpdateProgress(0.7);
    }

    convertMeshLagrangian(lagrangianOutput, blockNo);

    reader_->UpdateProgress(0.8);

    // Update fields
    convertVolFields(output);
    convertPointFields(output);
    convertLagrangianFields(lagrangianOutput);
    if (debug)
    {
        Info<< "done reader part" << endl;
    }
    reader_->UpdateProgress(0.95);

    meshChanged_ = fieldsChanged_ = false;
}


void Foam::vtkPVFoam::CleanUp()
{
    // reclaim some memory
    reduceMemory();
    reader_->UpdateProgress(1.0);
}


double* Foam::vtkPVFoam::findTimes(int& nTimeSteps)
{
    int nTimes = 0;
    double* tsteps = nullptr;

    if (dbPtr_.valid())
    {
        Time& runTime = dbPtr_();
        // Get times list. Flush first to force refresh.
        fileHandler().flush();
        instantList timeLst = runTime.times();

        // find the first time for which this mesh appears to exist
        label timeI = 0;
        for (; timeI < timeLst.size(); ++timeI)
        {
            const word& timeName = timeLst[timeI].name();

            if
            (
                IOobject
                (
                    "points",
                    timeName,
                    meshDir_,
                    runTime
                ).typeHeaderOk<pointIOField>(true)
            )
            {
                break;
            }
        }

        nTimes = timeLst.size() - timeI;

        // skip "constant" time whenever possible
        if (timeI == 0 && nTimes > 1)
        {
            if (timeLst[timeI].name() == runTime.constant())
            {
                ++timeI;
                --nTimes;
            }
        }


        // skip "0/" time if requested and possible
        if (nTimes > 1 && reader_->GetSkipZeroTime())
        {
            if (mag(timeLst[timeI].value()) < small)
            {
                ++timeI;
                --nTimes;
            }
        }

        if (nTimes)
        {
            tsteps = new double[nTimes];
            for (label stepI = 0; stepI < nTimes; ++stepI, ++timeI)
            {
                tsteps[stepI] = timeLst[timeI].value();
            }
        }
    }
    else
    {
        if (debug)
        {
            cout<< "no valid dbPtr:\n";
        }
    }

    // vector length returned via the parameter
    nTimeSteps = nTimes;

    return tsteps;
}


void Foam::vtkPVFoam::renderPatchNames
(
    vtkRenderer* renderer,
    const bool show
)
{
    if (!meshPtr_)
    {
        return;
    }

    // always remove old actors first

    forAll(patchTextActorsPtrs_, patchi)
    {
        renderer->RemoveViewProp(patchTextActorsPtrs_[patchi]);
        patchTextActorsPtrs_[patchi]->Delete();
    }
    patchTextActorsPtrs_.clear();

    if (show)
    {
        // get the display patches, strip off any suffix
        wordHashSet selectedPatches = getSelected
        (
            reader_->GetPartSelection(),
            arrayRangePatches_
        );

        if (selectedPatches.empty())
        {
            return;
        }

        const polyBoundaryMesh& pbMesh = meshPtr_->boundaryMesh();

        // Find the total number of zones
        // Each zone will take the patch name
        // Number of zones per patch ... zero zones should be skipped
        labelList nZones(pbMesh.size(), 0);

        // Per global zone number the average face centre position
        List<DynamicList<point>> zoneCentre(pbMesh.size());


        // Loop through all patches to determine zones, and centre of each zone
        forAll(pbMesh, patchi)
        {
            const polyPatch& pp = pbMesh[patchi];

            // Only include the patch if it is selected
            if (!selectedPatches.found(pp.name()))
            {
                continue;
            }

            const labelListList& edgeFaces = pp.edgeFaces();
            const vectorField& n = pp.faceNormals();

            boolList featEdge(pp.nEdges(), false);

            forAll(edgeFaces, edgeI)
            {
                const labelList& eFaces = edgeFaces[edgeI];

                if (eFaces.size() == 1)
                {
                    // Note: could also do ones with > 2 faces but this gives
                    // too many zones for baffles
                    featEdge[edgeI] = true;
                }
                else if (mag(n[eFaces[0]] & n[eFaces[1]]) < 0.5)
                {
                    featEdge[edgeI] = true;
                }
            }

            // Do topological analysis of patch, find disconnected regions
            patchZones pZones(pp, featEdge);

            nZones[patchi] = pZones.nZones();

            labelList zoneNFaces(pZones.nZones(), 0);

            // Create storage for additional zone centres
            forAll(zoneNFaces, zoneI)
            {
                zoneCentre[patchi].append(Zero);
            }

            // Do averaging per individual zone
            forAll(pp, facei)
            {
                label zoneI = pZones[facei];
                zoneCentre[patchi][zoneI] += pp[facei].centre(pp.points());
                zoneNFaces[zoneI]++;
            }

            forAll(zoneCentre[patchi], zoneI)
            {
                zoneCentre[patchi][zoneI] /= zoneNFaces[zoneI];
            }
        }

        // Count number of zones we're actually going to display.
        // This is truncated to a max per patch

        const label MAXPATCHZONES = 20;

        label displayZoneI = 0;

        forAll(pbMesh, patchi)
        {
            displayZoneI += min(MAXPATCHZONES, nZones[patchi]);
        }

        if (debug)
        {
            Info<< "displayed zone centres = " << displayZoneI << nl
                << "zones per patch = " << nZones << endl;
        }

        // Set the size of the patch labels to max number of zones
        patchTextActorsPtrs_.setSize(displayZoneI);

        if (debug)
        {
            Info<< "constructing patch labels" << endl;
        }

        // Actor index
        displayZoneI = 0;

        forAll(pbMesh, patchi)
        {
            const polyPatch& pp = pbMesh[patchi];

            label globalZoneI = 0;

            // Only selected patches will have a non-zero number of zones
            label nDisplayZones = min(MAXPATCHZONES, nZones[patchi]);
            label increment = 1;
            if (nZones[patchi] >= MAXPATCHZONES)
            {
                increment = nZones[patchi]/MAXPATCHZONES;
            }

            for (label i = 0; i < nDisplayZones; i++)
            {
                if (debug)
                {
                    Info<< "patch name = " << pp.name() << nl
                        << "anchor = " << zoneCentre[patchi][globalZoneI] << nl
                        << "globalZoneI = " << globalZoneI << endl;
                }

                vtkTextActor* txt = vtkTextActor::New();

                txt->SetInput(pp.name().c_str());

                // Set text properties
                vtkTextProperty* tprop = txt->GetTextProperty();
                tprop->SetFontFamilyToArial();
                tprop->BoldOff();
                tprop->ShadowOff();
                tprop->SetLineSpacing(1.0);
                tprop->SetFontSize(12);
                tprop->SetColor(1.0, 0.0, 0.0);
                tprop->SetJustificationToCentered();

                // Set text to use 3-D world co-ordinates
                txt->GetPositionCoordinate()->SetCoordinateSystemToWorld();

                txt->GetPositionCoordinate()->SetValue
                (
                    zoneCentre[patchi][globalZoneI].x(),
                    zoneCentre[patchi][globalZoneI].y(),
                    zoneCentre[patchi][globalZoneI].z()
                );

                // Add text to each renderer
                renderer->AddViewProp(txt);

                // Maintain a list of text labels added so that they can be
                // removed later
                patchTextActorsPtrs_[displayZoneI] = txt;

                globalZoneI += increment;
                displayZoneI++;
            }
        }

        // Resize the patch names list to the actual number of patch names added
        patchTextActorsPtrs_.setSize(displayZoneI);
    }
}


void Foam::vtkPVFoam::PrintSelf(ostream& os, vtkIndent indent) const
{
    os  << indent << "Number of nodes: "
        << (meshPtr_ ? meshPtr_->nPoints() : 0) << "\n";

    os  << indent << "Number of cells: "
        << (meshPtr_ ? meshPtr_->nCells() : 0) << "\n";

    os  << indent << "Number of available time steps: "
        << (dbPtr_.valid() ? dbPtr_().times().size() : 0) << "\n";

    os  << indent << "mesh region: " << meshRegion_ << "\n";
}


// ************************************************************************* //
